AVS 65th International Symposium & Exhibition
    Fundamental Discoveries in Heterogeneous Catalysis Focus Topic Thursday Sessions
       Session HC-ThP

Paper HC-ThP4
In-Operando Photoluminescence Imaging of a Single-Layer Molybdenum Disulfide Catalyst

Thursday, October 25, 2018, 6:00 pm, Room Hall B

Session: Fundamental Discoveries in Heterogeneous Catalysis Focus Topic Poster Session
Presenter: Koichi Yamaguchi, University of California - Riverside
Authors: K.Y. Yamaguchi, University of California - Riverside
S. Naghibi, University of California, Riverside
W. Coley, University of California, Riverside
L. Bartels, University of California, Riverside
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MoS2 is the key industrial catalyst for hydrodesulfurization (HDS) of crude oil. Atomistic investigation of the HDS reaction is hampered by the elevated pressures and temperatures required for HDS. There is close correlation between the current industrial catalyst material and model single-layer MoS2 flakes. We developed a new experimental approach that relies on strong photoluminescence (PL) of monolayer MoS2 that we grow efficiently on an inert SiO2 substrate. We find that wide-field PL imaging is possible even under near in-operando condition and can serve as a reporter of the chemical state and spatial variation of the catalyst material. Our experiments proceed under up to 1atm of hydrogen, any volatile thiol, and at temperatures of up to 400 °C. Spatially resolved images allow us to distinguish between reactions at island edges and the basal plane; desulfurization and binding of organic species to the catalyst are reported as bleaching of the photoluminescence. Concomitant mass spectrometric analysis allows us to correlate the variation in the island PL with different reaction regimes.